R shiny - 101

ui <- fluidPage(
  numericInput(inputId = "num", 
               label = "Number one", 
               value = 0, min = 0, max = 100)
)

ui <- fluidPage(
  plotOutput(outputId = "plot")
)
server <- function(input, output, session) {
  output$plot <- renderPlot(plot(1:5))
}

ui <- fluidPage(
  numericInput(inputId = "count", 
               label = "Number of values", 
               value = 100)
)
server <- function(input, output, session) {
  message("The value of input$count is ", input$count)
}

shinyApp(ui, server)
#> Error: Can't access reactive value 'count' outside of reactive consumer.
#> ℹ Do you need to wrap inside reactive() or observer()?

ui <- fluidPage(
  numericInput(inputId = "count", 
               label = "Number of values", 
               value = 100),
  textOutput(outputId = "message")
)
server <- function(input, output, session) {
  output$message("The value of input$count is ", input$count)
}

shinyApp(ui, server)

ui <- fluidPage(
  textOutput("greeting")
)

server <- function(input, output, session) {
  output$greeting <- renderText("Hello human!")
}

# load packages
library(shiny)
library(dplyr)
library(ggplot2)

# load data
data_tdr = readRDS("../export/data_tdr.rds")

# define UI for the application
ui <- fluidPage(
  
#  # application title
#  titlePanel("TDR Data"),
#
#  # sidebar layout = sidebar panel + main panel
#  sidebarLayout(
#
#    # sidebar panel = sliderInput + radioButtons + checkboxGroupInput
#    sidebarPanel(
      
      ####### TO BE COMPLETED ########
      # sliderInput to choose the number of dives
      sliderInput(...),
      ################################
      
      # radioButtons to decide the color code
      radioButtons(inputId = "color_code",
                   label = "Color code:",
                   choices = c("Yes", "No"),
                   selected = c("No")),
      
      # checkboxGroupInput to select dive types
      checkboxGroupInput(inputId = "dive_type", 
                         label = "Dive types:", 
                         choices = unique(data_tdr$dive_type),
                         selected = unique(data_tdr$dive_type)),
#    ),
    
    # mainPanel = plotOutput
#    mainPanel(
      # plotOutput to display main_plot
      plotOutput(outputId = "main_plot")
#    )
#  )
)

# define server logic required to draw the plot
server <- function(input, output) {
  
  # store the plot
  output$main_plot <- renderPlot({
    
    # from data_tdr
    data_tdr %>% 
      # filter on the number of dives from the sliderInput in the ui
      filter(dive_number <= input$nb_dives) %>%
      
      ####### TO BE COMPLETED ########
      # filter on the dive type from the checkboxGroupInput in the ui
      
      ################################
      
      # initiate a plot
      ggplot(aes(x = datetime, 
                 y = depth,
                 group = dive_number))+
      # which going to be a geom_path = line plot
      geom_path(
        # if color_code == Yes
        mapping = if(input$color_code == "Yes"){
          # then use dive_type as color_code
          aes(col = dive_type)
        }
      ) 
#    +
#      ### everything below is optional ###
#      # tweak y axis
#      scale_y_reverse(
#        # a proper name
#        name = "Depth (m)",
#        # fix the limits, note: use rev because we reversed the y axis
#        limits = rev(range(data_tdr$depth))) +
#      # tweak x axis
#      scale_x_datetime(
#        # a proper name
#        name = "Time",
#        # ticks frequency
#        date_breaks = "20 mins",
#        # format of labels
#        date_labels = "%H:%M",
#        # position
#        position = "top",
#        # fix the limits
#        limits = range(data_tdr$datetime)) +
#      # tweak color
#      scale_color_manual(
#        # fix color for each dive type
#        values = c(Forage = "#00AFBB", 
#                   Transit = "#E7B800", 
#                   Drift = "#FC4E07")) +
#      # rename title of the legend
#      labs(col = "Dive Type") +
#      # choose a theme
#      theme_minimal() +
#      # and tweak it
#      theme(
#        # legend position
#        legend.position = "bottom",
#        # add arrow for x axis
#        axis.line.x = element_line(arrow = arrow(
#          ends = "last",
#          type = "closed",
#          length = unit(0.25, "npc"))),
#        # add arrow for y axis
#        axis.line.y = element_line(arrow = arrow(
#          ends = "first",
#          type = "closed",
#          length = unit(0.25, "npc"))))
  })
}

# Run the application 
shinyApp(ui = ui, server = server)